Laminate structures may be used for a wide range of applications in a variety of industries. For example, laminate structures may be used in architectural applications such as siding, decorative panels, cabinet installations, wall coverings, and the like. Laminate structures may also be used for furniture items and/or household appliances. For instance, laminate structures may be incorporated as outer panels for a cabinet, furniture item, and/or household appliance. Laminate structures can further serve as functional or decorative components in automobiles, e.g., windows, sunroofs, mirrors, and exterior or interior paneling.
Automotive, transportation, aviation, and architectural windows are often made from laminate structures comprising two glass sheets of similar thickness and composition. However, for various applications it may be desirable to provide laminate structures comprising dissimilar substrates, e.g., substrates of different composition and/or thickness. For instance, metal-glass laminates, plastic-glass laminates, glass-ceramic laminates, and other similar laminates may be desirable for aesthetic or structural qualities.
In addition, glass-glass laminates comprising dissimilar glass substrates may also be desirable for various applications, for example, laminates comprising glasses having different compositions, thicknesses, and/or other properties such as coefficient of thermal expansion (CTE). By way of a non-limiting example, a thin sheet of ion-exchanged glass may be laminated on a thicker soda lime glass sheet to provide enhanced damage resistance. Electrochromic windows and mirrors can comprise a thin, alkali-free glass substrate upon which an electrically active thin film is deposited, which can be laminated to a thicker soda lime glass substrate for enhanced structural rigidity.
Laminate structures comprising dissimilar substrates are referred to herein as “asymmetric” laminates. While asymmetric laminates may present one or more advantages as compared to symmetric laminates, these laminates can also present various challenges. For example, asymmetric laminates can comprise two or more substrates with different CTEs. During the lamination process, the substrates can be heated to a lamination temperature and subsequently cooled, e.g., to room temperature. When the laminate structure cools, the CTE mismatch between the substrates can lead to out-of-plane deflection (often referred to as “bow”). Bow in laminate structures can interfere with subsequent processing steps such as film deposition, can result in unwanted optical distortion in the final product, and/or can result in a product that is unsuitable for the intended application and/or does not meet the desired target shape.
Accordingly, it would be advantageous to provide methods for making laminate structures that can reduce or eliminate bow in the structures after cooling. It would also be advantageous to provide asymmetric laminate structures with little or no out-of-plane deflection or bow. These and other aspects of the disclosure are discussed in further detail herein.